Dual Section Module Having Shared and Unshared Mass Flow Controllers

ABSTRACT

A dual section module with mass flow controllers, for processing wafers, includes: dual process sections integrated together; at least one mass flow controller (MFC) each shared by the dual process sections and provided in a gas line branching into two gas lines, at a branching point, connected to the respective interiors of the dual process sections and arranged symmetrically between the dual process sections; and at least one mass flow controller (MFC) each unshared by the dual process sections and provided in a gas line connected to the interior of each dual process section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a dual section module equipped with mass flow controllers, particularity to such a dual section module having mass flow controllers shared and unshared by the dual sections.

2. Description of the Related Art

Conventionally, mass flow controllers (MFC's) are provided per reaction section, since the MFC's are calibrated for an individual reactor. However, the present inventor recognized that when simultaneous dual wafer processing is performed using a dual section module, two sets of MFC's for the dual sections require some space and are not economical. However, sharing MFC's between the dual sections causes problems that when a difference between the dual sections is detected, it is difficult to control the dual sections individually for adjusting the difference.

Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.

SUMMARY OF THE INVENTION

Some embodiments provide a dual section module which is space-effective, cost-effective, and highly-controllable.

Some embodiments provide a dual section module with mass flow controllers, for processing wafers, comprising: (i) dual process sections integrated together, each being adapted to process a wafer in its interior, wherein the interiors of the dual process sections are isolated and discrete from each other; (ii) at least one mass flow controller (MFC) each of which is shared by the dual process sections and provided in a gas line branching into two gas lines, at a branching point, connected to the respective interiors of the dual process sections and arranged symmetrically between the dual process sections; (iii) at least one mass flow controller (MFC) each of which is unshared by the dual process sections and provided in a gas line connected to one of the interiors of the dual process sections; and (iv) at least one mass flow controller (MFC) each of which is unshared by the dual process sections and provided in a gas line connected to the other of the interiors of the dual process section.

In some embodiments, the gas line upstream of each shared MFC is connected to a source of a gas which does not constitute a main skeleton of a film depositing on the wafer, and each of the gas lines upstream of the respective unshared MFC's is connected to a source of a gas which constitutes the main skeleton of the film depositing on the wafer. In some embodiments, the gas which constitutes the main skeleton of the film is a precursor gas. In some embodiments, the gas which does not constitute the main skeleton of the film is an inert gas or oxidizing gas.

In some embodiments, the two gas lines branched off at the branching point from the gas line in which the shared MFC is provided are connected to respective showerheads of the dual process sections. In some embodiments, the two gas lines are provided with passage-narrowing devices, respectively, downstream of the branching point and upstream of the respective dual process sections. In some embodiments, the dual section module further comprises remote plasma units, each connected to a gas line extending from each passage-narrowing device to each dual process section, wherein another mass flow controller (MFC) shared by the dual process sections is provided in a gas line branching into two gas lines upstream of the respective remote plasma units, said two gas lines being connected to the respective remote plasma units and provided with passage-narrowing devices, respectively.

In some embodiments, the at least one mass flow controller (MFC) is comprised of multiple shared MFC's which are disposed in parallel and converged and connected to the gas line branching into the two gas lines upstream of the branching point.

In some embodiments, the at least one mass flow controller (MFC) connected to the gas line connected to the one of the interiors of the dual process sections is comprised of multiple unshared MFC's which are disposed in parallel and converged and connected to the gas line connected to the one of the interiors of the dual process sections, and the at least one mass flow controller (MFC) connected to the gas line connected to the other of the interiors of the dual process sections is comprised of multiple unshared MFC's which are disposed in parallel and converged and connected to the gas line connected to the other of the interiors of the dual process sections.

In some embodiments, the two gas lines branched off at a branching point from the gas line in which the shared MFC is provided are connected to the respective dual process sections at their lower portions under respective susceptors. In some embodiments, the two gas lines are further provided with passage-narrowing devices, respectively, downstream of the branching point and upstream of the respective dual process sections. In some embodiments, the upstream of the gas line in which the shared MFC is provided is connected to a source of a seal gas.

In some embodiments, the dual section module further comprises a single gas box which stores and consolidates inside the shared MFC for the dual process sections, the unshared MFC for the one of the dual process sections, and the unshared MFC for the other one of the dual process sections, said gas box constituting a module and being disposed under the dual section module.

In some embodiments, the process sections are plasma CVD sections.

Some embodiments provide a wafer-processing apparatus comprising: (a) multiple dual section modules according to any of the disclosed embodiments; and (b) a wafer-handling section to which the multiple dual section modules are attached on the same plane.

In some embodiments, the multiple dual section modules are four dual section modules, and the wafer-handling section has a pentagonal shape having five sides, to four of which the four dual section modules are attached.

Some embodiments provide a method for processing wafers using any of the disclosed dual section modules, comprising: (A) placing wafers in the dual process sections, respectively; (B) introducing a first gas which does not constitute a main skeleton of a film to be deposited on each wafer, to the dual process sections using the shared MFC; (C) introducing a second gas which constitutes the main skeleton of the film to the dual process sections using the respective unshared MFC's; and (D) depositing the film on each wafer using the first and second gases.

In some embodiments, the first gas is a rare gas, oxidizing gas, or inert gas other than rare gas. In some embodiments, the second gas is a precursor gas. In some embodiments, the method further comprises introducing a seal gas into the dual process sections using the shared MFC.

For purposes of summarizing aspects of the invention and the advantages achieved over the related art, certain objects and advantages of the invention are described in this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

Further aspects, features and advantages of this invention will become apparent from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will now be described with reference to the drawings of preferred embodiments which are intended to illustrate and not to limit the invention. The drawings are greatly simplified for illustrative purposes and are not necessarily to scale.

FIG. 1 is a schematic representation of a dual chamber module with gas lines according to an embodiment of the present invention.

FIG. 2 is a schematic representation of a dual chamber module and a gas box according to an embodiment of the present invention.

FIG. 3 is a schematic plan view of a plasma CVD apparatus including gas boxes and electric boxes according to an embodiment of the present invention.

FIG. 4 is a schematic perspective view of a plasma CVD apparatus including gas boxes and electric boxes according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

In this disclosure, “gas” may include vaporized solid and/or liquid and may be constituted by a mixture of gases. In this disclosure, the reactive gas, the additive gas, and the hydrogen-containing silicon precursor may be different from each other or mutually exclusive in terms of gas types, i.e., there is no overlap of gas types among these categories. Gases can be supplied in sequence with or without overlap. In this disclosure, “precursor” refers to a material which constitutes a main skeleton of a film to be deposited on a wafer, a material which provides an element or elements constituting a main skeleton of a film to be deposited on a wafer, and/or a material whose flow rate fluctuation affects the quality of a film to be deposited on a wafer substantially more than do other materials used for depositing the film. The “main skeleton” refers to a structure which characterizes a film or mainly or predominantly constitutes the structure of a film.

In this disclosure, “dual process sections” or “dual sections” refers to two sections disposed closely to each other and viewed substantially as e.g. physically, functionally, and/or cognitively separated or isolated from each other, which include, but are not limited to, dual chambers which are physically, structurally, and operationally separated from each other (e.g., two separate process chambers connected to each other), and dual regions which are cognitively and positionally isolated from each other (e.g., two isolated process regions disposed in one chamber).

In some embodiments, “mass flow controller” (MFC) refers to a device designed and calibrated to control a specific type of fluid or gas at a particular range (a setpoint) of flow rates. The MFC can be given a setpoint from 0 to 100% of its full scale range but is typically operated in the range of 10 to 90% of full scale where the best accuracy is achieved. The MFC can be either analog or digital. The MFC typically has an inlet port, an outlet port, a mass flow sensor and a proportional control valve. The MFC can be given an input signal by an operator (or an external circuit/computer) that it compares to the value from the mass flow sensor and adjusts the proportional valve accordingly to achieve the required flow. In some embodiments, the flow rate is specified as a percentage of its calibrated full scale flow and is supplied to the MFC as a voltage signal.

In the present disclosure where conditions and/or structures are not specified, the skilled artisan in the art can readily provide such conditions and/or structures, in view of the present disclosure, as a matter of routine experimentation. Also, in the present disclosure including the examples described later, the numbers applied in specific embodiments can be modified by a range of at least ±50% in some embodiments, and the ranges applied in some embodiments may include or exclude the lower and/or upper endpoints. Further, the numbers include approximate numbers, and may refer to average, median, representative, majority, etc. in some embodiments.

In all of the disclosed embodiments, any element used in an embodiment can interchangeably or additionally be used in another embodiment unless such a replacement is not feasible or causes adverse effect or does not work for its intended purposes. Further, the present invention can equally be applied to apparatuses and methods.

In the disclosure, “substantially the same”, “substantially uniform”, or the like may refer to a difference recognized by a skilled artisan such as those of less than 10%, less than 5%, less than 1%, or any ranges thereof in some embodiments. Also, in the disclosure, “substantially smaller”, “substantially different”, “substantially less” or the like may refer to a difference recognized by a skilled artisan such as those of at least 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or any ranges thereof in some embodiments.

In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments.

The embodiments will be explained with respect to preferred embodiments. However, the present invention is not limited to the preferred embodiments.

FIG. 1 is a schematic representation of a dual chamber module with gas lines according to an embodiment. This module is constituted by a right reaction chamber (RCR) and a left reaction chamber (RCL). The reaction chamber RCR and the reaction chamber RCL are discrete and separated from each other, i.e., the interior of the reaction chamber RCR and the interior of the reaction chamber RCL are not gas-communicated with each other. In the reaction chamber RCR, a showerhead 2R and a susceptor 3R are provided, and in the reaction chamber RCL, a showerhead 2L and a susceptor 3L are provided.

A precursor gas which will constitute a main skeleton of a film to be deposited on a wafer on the susceptor is introduced into the reaction chamber RCR and the reaction chamber RCL using unshared mass flow controllers 5R, 5L. A gas other than the precursor, such as a rare gas, other inert gas, oxidizing gas, other additive gas, or cleaning gas, which will not constitute a main skeleton of a film to be deposited on a wafer on the susceptor, is introduced into the reaction chamber RCR and the reaction chamber RCL using a shared mass flow controller 4. A gas line in which the mass flow controller 4 is provided is forked into two gas lines which are connected to the showerheads 2R, 2L, respectively. The two gas lines (i.e., gas flows therein and gas flow patterns) are arranged substantially symmetrically between the reaction chambers RCR, RCL (left-right symmetry or mirror arrangement) from the forking point to the reaction chambers. In some embodiments, in order to improve even distribution of the gas into the two gas lines, orifices 7R, 7L are provided as passage-narrowing devices in the respective gas lines upstream of respective gas mixing points 10R, 10L and downstream of the mass flow controller 4, so that the gas flows passing through the two gas lines are substantially the same. In some embodiments, as passage-narrowing devices, needle valves, filters, etc. are used. In some embodiments, a seal gas is introduced into the reaction chambers RCR, RCL using a shared mass flow controller 6. A gas line in which the mass flow controller 6 is provided is forked into two gas lines which are connected to the reaction chambers RCR, RCL at their bottoms (e.g., in wafer-transfer zones). In some embodiments, in order to improve even distribution of the gas into the two gas lines, orifices 8R, 8L are provided as passage-narrowing devices in the respective gas lines upstream of respective reaction chambers RCR, RCL and downstream of the miss flow controller 6 so that the gas flows passing through the two gas lines are substantially the same. Gases are discharged from the reaction chambers RCR, RCL using exhaust lines 9R, 9L.

As the precursor or primary gas, any suitable liquid materials and any suitable gaseous materials can be used singly or in any combination of two or more materials depending on the intended use, and can be introduced into reaction chambers via unshared mass flow controllers. For example, the precursor is a silicon-containing precursor such as silane, TEOS, alkylsilanes, alkoxysilanes, aminosilanes, siloxanes, nitroalkylsiloxanes, etc. In some embodiments, the liquid material is stored in a container and its vapor phase is discharged from the container together with a carrier gas. In some embodiments, the precursor is a carbon-containing precursor such as hexane, propyl alcohol, etc. In some embodiments, the precursor is a nitrogen-containing precursor such as NH₃, amines, etc. In some embodiments, the precursor is a material containing metal elements such as Ru, Ti, Ta, As, Ge, B, etc. In some embodiments, as the secondary gas (which is gas other than the precursor), a rare gas such as Ar, He, Kr, Xe, etc., an oxidizing gas such as O₂, N₂O, CO₂, etc., and other additive gas such as H, N₂, etc. can be used singly or in any combination of two or more gases, and can be introduced into reaction chambers via at least one shared mass flow controller. In some embodiments, NH₃ can be used as a secondary gas, not as a primary gas, if the flow rate is more than about 100 sccm. Also, in some embodiments, N2 can be used as a primary gas or precursor gas (dopant gas), not as a secondary gas. In some embodiments, the secondary gas includes a cleaning gas such as NF₃, CF₄, etc.

FIG. 2 is a schematic representation of a dual chamber module and a gas box, desirably in conjunction with controls programmed to conduct sequences, which can be used in an embodiment of the present invention. The dual chamber module is constituted by a reaction chamber 25R and a reaction chamber 25L which are isolated and discrete chambers in terms of gas communication therebetween. A gas box 27 contains mass flow controllers, valves, gas lines, and bubbling unit 28. There are four main gas lines 11, 12, 13, 14 coming out from the gas box 27 and connected to the reaction chambers 25R, 25L. The gas line 11 is connected to a showerhead of the reaction chamber 25R for processing a wafer in the reaction chamber 25R, the gas line 12 is connected to a showerhead of the reaction chamber 25L for processing a wafer in the reaction chamber 25L, the gas line 13 is connected to remote plasma units 26R, 26L for cleaning the reaction chambers 25R, 25L, respectively, and the gas line 14 is connected to transfer zones of the reaction chambers 25R, 25L for sealing reaction zones of the reaction chambers 25R, 25L. There is another gas line 15 coming out from the gas box 27 for releasing purge gas N₂.

In some embodiments, He, O₂, N₂O, and N₂ can be introduced separately or simultaneously as secondary gases into the reaction chambers 25R, 25L using shared mass flow controllers (MFC's) 21 d, 21 e, 21 f/21 g, and 21 h/21 i, respectively. The shared MFC's 21 d, 21 e, 21 f/21 g, and 21 h/21 i are disposed in parallel and converged to a single gas line leading to a branching point 18 and branching off into the two gas lines 11, 12. The two gas lines 11, 12 are provided with orifice gaskets 19R, 19L, respectively, so that the gas flows passing through the gas lines 11, 12 are substantially the same. NH₃ can also be introduced into the reaction chambers 25R, 25L as a secondary gas when its flow rate is greater than about 100 sccm, for example, via a shared MFC 21 j connected to the branching point 18. In some embodiments, TEOS can be introduced as a primary gas or precursor gas into the reaction chamber 25R, 25L, via unshared MFC's 22 e, 22 f, respectively. The unshared MFC's 22 e, 22 f are connected to the gas lines 11, 12 at joint points 41, 42, respectively, downstream of the orifice gaskets 19R, 19L so that the gas flows passing through the gas lines 11, 12 are substantially the same. Since TEOS is a liquid material at room temperature, a bubbling unit 28 is used to vaporize the liquid material and discharge a gaseous phase of the liquid material together with a carrier gas to the unshared MFC's 22 e, 22 f. In order to purge TEOS, N₂ can be introduced upstream of the bubbling unit 28 and discharged via the gas line 15, and N₂ can also be introduced downstream of the bubbling unit 28. SH4 also can be introduced as a precursor gas to the reaction chambers 25R, 25L via unshared MFC's 22 c, 22 d, respectively, which are connected to the gas lines 11, 12, respectively. NH₃ also can be introduced as a precursor gas to the reaction chambers 25R, 25L via unshared MFC's 22 a, 22 b, respectively, which are connected to the gas lines 11, 12, respectively. N2 also can be introduced as a precursor gas to the reaction chambers 25R, 25L via unshared MFC's 22 c, 22 d, respectively, which are connected to the gas lines 11, 12, respectively. These MFC's are disposed in parallel and converge either the gas line 11 or the gas line 12. In the above, the gas lines 11, 12 from the branching point 18 to the showerheads of the reaction chambers 25R, 25L are arranged substantially symmetrically between the reaction chambers 25R, 25L.

In some embodiments, Ar and NF3/N2 can be introduced into the reaction chambers 25R, 25L as a cleaning gas via shared MFC's 21 a, 21 b, respectively, which are disposed in parallel and provided in gas lines which are converged to a gas line which branches off at branching point 17 into two gas lines which are connected to the remote plasma 26R, 26L, respectively, and are provided with orifice gaskets 23R, 23L, respectively. In some embodiments, the orifice gaskets 23R, 23L are not disposed inside the gas box 27. The remote plasma units 23R, 23L are connected to the gas lines 11, 12 downstream of the joint points 41, 42 and upstream of the reaction chambers 25R, 25L. In some embodiments, He can be introduced into the reaction chambers 25R, 25L as a seal gas via shared MFC 21 c provided in a gas line which branches off at a branching point 16 into two gas lines which are connected to transfer zones of the reaction chambers 25R, 25L, respectively, and are provided with orifice gaskets 24R, 24L, respectively. The reaction chambers 25R, 25L can be evacuated using a dry pump 29. In this figure, “PT” refers to pressure transducer, and “CM” refers to capacitance manometer. In the above, the gas lines from the branching point 17 to the showerheads of the reaction chambers 25R, 25L are arranged substantially symmetrically between the reaction chambers 25R, 25L. Likewise, in the above, the gas lines from the branching point 16 to the transfer zones of the reaction chambers 25R, 25L are arranged substantially symmetrically between the reaction chambers 25R, 25L.

A skilled artisan will appreciate that the above apparatus includes one or more controller(s) (not shown) programmed or otherwise configured to cause the deposition and reactor cleaning processes described elsewhere herein to be conducted. The controller(s) are communicated with the various power sources, heating systems, pumps, robotics and gas flow controllers or valves of the reactor, as will be appreciated by the skilled artisan.

In some embodiments, multiple dual chamber modules are attached to a wafer-handling chamber provided with a back end robot (vacuum robot), constituting a multiple-module platform. In some embodiments, since the gas controlling mechanisms are consolidated to a gas box as illustrated in FIG. 2, the gas box is integrated with the dual chamber module, constituting a combined module. Further, in some embodiments, electrical controlling mechanisms are consolidated to an electric box which is integrated with the gas box and the dual chamber module, constituting a combined module.

As illustrated in FIGS. 3 and 4, in some embodiments, gas boxes 31 a, 31 b, 31 c, 31 d and electric boxes 32 a, 32 b, 32 c, 32 d are arranged alternately as viewed from above, corresponding to and underneath process modules (PM1, PM2, PM3, PM4), respectively. The modules PM1, PM2, PM3, PM4 are attached to a wafer-handling chamber (WHC) provided with a back end robot (BERB). A load lock chamber (LLC) is also attached to the wafer-handling chamber WHC. An equipment front end module (EFEM) 6 provided with a front end robot (FERB) is attached to the other side of the load lock chamber LLC. Four loading ports (LP1, LP2, LP3, LP4) are attached to the other side of the equipment front end module EFEM. The electric boxes 32 a, 32 b, 32 c, 32 d can be pulled out outwardly without being disconnected from the corresponding modules so that sides of the gas boxes are accessible. In some embodiments, the electric boxes have casters at their bottoms so that they can easily be pulled out for maintenance. FIG. 4 shows the gas box 31 c and the electric box 32 c disposed under the module PM3. In some embodiments, as shown in FIGS. 3 and 4, the gas boxes and the electric boxes have an approximately trapezoidal shape having an inner face and an outer face as viewed from above wherein the inner face is shorter than the outer face as viewed from above. Also as shown in FIGS. 3 and 4, in some embodiments, the side faces of the gas boxes and side faces of the electric boxes are closely disposed or are in contact with each other, so that the width of the apparatus can be reduced. In some embodiments, even if the apparatus has eight rectors (four modules), its width is smaller than that of a conventional apparatus having six reactors (three modules). In some embodiments, the disclosed dual chamber modules can be used in the apparatus disclosed in a co-pending U.S. patent application Ser. No. 13/154,271, the disclosure of which is herein incorporated by reference in its entirety. A skilled artisan will appreciate that the above apparatus includes one or more controller(s) (not shown) programmed or otherwise configured to cause the deposition and reactor cleaning processes described elsewhere herein to be conducted. The controller(s) is/are communicated with the various power sources, heating systems, pumps, robotics and gas flow controllers or valves of the reactor, as will be appreciated by the skilled artisan.

It will be understood by those of skill in the art that numerous and various modifications can be made without departing from the spirit of the present invention. Therefore, it should be clearly understood that the forms of the present invention are illustrative only and are not intended to limit the scope of the present invention. 

1. A dual section module with mass flow controllers, for processing wafers, comprising: dual process sections integrated together, each being adapted to process a wafer in its interior, wherein the interiors of the dual process sections are isolated and discrete from each other; at least one mass flow controller (MFC) each shared by the dual process sections and provided in a gas line branching into two gas lines, at a branching point, connected to the respective interiors of the dual process sections and arranged symmetrically between the dual process sections; at least one mass flow controller (MFC) each unshared by the dual process sections and provided in a gas line connected to one of the interiors of the dual process sections; and at least one mass flow controller (MFC) each unshared by the dual process sections and provided in a gas line connected to the other of the interiors of the dual process section.
 2. The dual section module according to claim 1, wherein the gas line upstream of each shared MFC is connected to a source of a gas which does not constitute a main skeleton of a film depositing on the wafer, and each of the gas lines upstream of the respective unshared MFC's is connected to a source of a gas which constitutes the main skeleton of the film depositing on the wafer.
 3. The dual section module according to claim 2, wherein the gas which constitutes the main skeleton of the film is a precursor gas.
 4. The dual section module according to claim 2, wherein the gas which does not constituted the main skeleton of the film is an inert gas or oxidizing gas.
 5. The dual section module according to claim 1, wherein the two gas lines branched off at the branching point from the gas line in which the shared MFC is provided are connected to respective showerheads of the dual process sections.
 6. The dual section module according to claim 5, wherein the two gas lines are provided with passage-narrowing devices, respectively, downstream of the branching point and upstream of the respective dual process sections.
 7. The dual section module according to claim 6, further comprising remote plasma units, each connected to a gas line extending from each passage-narrowing device to each dual process section, wherein another mass flow controller (MFC) shared by the dual process sections is provided in a gas line branching into two gas lines upstream of the respective remote plasma units, said two gas lines being connected to the respective remote plasma units and provided with passage-narrowing devices, respectively.
 8. The dual section module according to claim 1, wherein the at least one mass flow controller (MFC) is comprised of multiple shared MFC's which are disposed in parallel and converged and connected to the gas line branching into the two gas lines upstream of the branching point.
 9. The dual section module according to claim 1, wherein the at least one mass flow controller (MFC) connected to the gas line connected to the one of the interiors of the dual process sections is comprised of multiple unshared MFC's which are disposed in parallel and converged and connected to the gas line connected to the one of the interiors of the dual process sections, and the at least one mass flow controller (MFC) connected to the gas line connected to the other of the interiors of the dual process sections is comprised of multiple unshared MFC's which are disposed in parallel and converged and connected to the gas line connected to the other of the interiors of the dual process sections.
 10. The dual section module according to claim 1, wherein the two gas lines branched off at a branching point from the gas line in which the shared MFC is provided are connected to the respective dual process sections at their lower portions under respective susceptors.
 11. The dual section module according to claim 10, wherein the two gas lines are further provided with passage-narrowing devices, respectively, downstream of the branching point and upstream of the respective dual process sections.
 12. The dual section module according to claim 10, wherein the upstream of the gas line in which the shared MFC is provided is connected to a source of a seal gas.
 13. The dual section module according to claim 1, further comprising a single gas box which stores and consolidates inside the shared MFC for the dual process sections, the unshared MFC for the one of the dual process sections, and the unshared MFC for the other one of the dual process sections, said gas box constituting a module and being disposed under the dual section module.
 14. The dual section module according to claim 1, wherein the process sections are plasma CVD sections.
 15. A wafer-processing apparatus comprising: multiple dual section modules according to claim 13; and a wafer-handling section to which the multiple dual section modules are attached on the same plane.
 16. The wafer-processing apparatus according to claim 15, the multiple dual section modules are four dual section modules, and the wafer-handling section has a pentagonal shape having five sides, to four of which the four dual section modules are attached.
 17. A method for processing wafers using the dual section module of claim 1, comprising: placing wafers in the dual process sections, respectively; introducing a first gas which does not constitute a main skeleton of a film to be deposited on each wafer, to the dual process sections using the shared MFC; introducing a second gas which constitutes the main skeleton of the film to the dual process sections using the respective unshared MFC's; and depositing the film on each wafer using the first and second gases.
 18. The method according to claim 17, wherein the first gas is a rare gas, oxidizing gas, or inert gas other than rare gas.
 19. The method according to claim 17, wherein the second gas is a precursor gas.
 20. The method according to claim 17, further comprising introducing a seal gas into the dual process sections using the shared MFC. 